Stoker-driving mechanism



Aug. 13, 1929. F, w HQLUCK 1,724,711

STOKER DRIVING MECHANI SM Filed'Feb. 27, 1924 4 sheets-sheet 1 lll/'LVIII l INYEHTOR 1 @d wrm@ ATTORNEYS.

Aug. 13, 1929. F. w. HoLLlcK STOKER DRIVING MECHANISM Filed Feb. 27, 1924 4 Sheets-Sheet 2 ,I INVENTOR hemd/wauw l ATTQRNEYS.

Aug. l13, 1929. F. w. HoLLlcK STOKER DRIVING IEGHARISI 4 Sheets-Sheet 3 Filed Feb. 27, 1924 INVENTOR ATTORNEYS.

F. w. HOLLICK s'roKER DRIVING MECHANISM Aug. 13, 1.929.

Filed Feb. 27, 1924 4 sheets-sheet 4 WM'LM ATTORNEYS Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

FREDERICK WILLIAM HOLLICK, F GOUROCK, SCOTLAND, ASSIGNOB TO THE BAYB- COCK @a WILCOX COMPANY, OE' BAYONN JERSEY.

E, NEW JERSEY, A. CORPORATION OF NEW STOXER-DRIVING Application led February 27, 1924, Serial Io. 695,408, and in Great Britain Hatch 7, 1923.

My present invention relates to mechanism for driving chain-grate stokers, and will be best understood from the following description and the appended drawings, in whichF ig. 1 is a side elevation and Fig. 2 a front elevation (with part of the casing removed) of one embodiment of my invention; Fig. 2a is an enlarged section along the shaft 24 of Fig. 2; Fig. 3 isa side elevation and F ig. 4 front elevation (with part of the cover removed), showing a modification; Figs. 5, 6 and 7 show one form for controllingr the rate of travel of the chain grate, Fig. 6 being a side elevation of such mechanism, Fig. 5 a section of Fig. 6 on the line 5-5 and Fig. 7 an end view of part ofthe mechanism shown in Fig. 6; Fig. 8 is another form of apparatus for controlling the rate of travel of the chain grate, and Fig. 9 shows a reverse-motion-stop brake.

Like reference characters indicate like parts in the several views.

In the arrangement shown in Figs. 1 and 2, the chain-grate-driven shaft 10 is supported in the usual manner to be moved horizontally with its supports in order to take up slack in the chain grate, the shaft 1U, as is well understood, being usuallyoutside of and in front of the furnace through which the chain grate operates.

ln the illustrative embodiment, the shaft 10 is driven from a motor 11 which is supported in a frame 12 pivotally supported at 13 on some fixed part of the stoker. The

f pivot 13 is preferably located substantially vertically above the center of the shaft 10 and a sufficient distance therefrom so that when the shaft l0 is moved horizontally, the are struck from the center 13 will be substantially straight, so that by providing a small amount of lost motion around the pivot 13, the shaft 10 may be moved to considerable distance either side of the vertical plane of the center 13 without binding the pivot.

The motor 11 transmits power to the shaft 10 through a belt 14 connected to a casing 15 containing gearing to be more specifically described hereafter, this gearing driving a. gear 16 meshing with. a gear 17 on a shaft 18 having a pinion 19 engaging a gear 20 on a shaft 21 having a pinion 22 engaging a gear 23 on the shaft 10. The casing l5 and gear 1G are on shaft 24. The shafts 18, 21

v horizontally,

and 24 are all supported in the frame 12. Since the motor 11 is supported in the frame 12, itis obvious that as the shaft l0 is moved the train of gears remain in fixed relation to the shaft 10 and the motor 11, so that adjustment of the position of the shaft 10 does not disturb the driving arrangement.

The arrangement shown in Figs. 3 and i is substantially the same as that shown in Figs. 1 and 2, except that the power is derived from some external source, such as a. motor, which transmits power to a drivin shaft 25 through a sprocket 26, the shaf 25 having a gear 27 meshing with a Igear 28 connected to the casing 15 which is substantially the same as the casing 15 in Fig. 2. A gear 16 transmits power to a train of gearing connected to the gear 23 on the driven shaft l0. A frame 12 is pivoted at 13', the power shaft 25 and the shafts on which the train of gears are supported being carried in this frame. The plvot 13 is located, as described in connection with Fig. 1, so that the shaft l() may be moved horizontally, and similarly the motion of the power shaft 25 will preferably be in such a direction as not to materially affect its driving relation with its motor.

Because of varying operative conditions it is desirable to regulate the rate of travel of the chain grate. Vhile, of course, this could be done by changing the speed of the power shaft or of themotor driving the grate, this is not desirable, and I have provided a means by which the rate of travel of the grate may be regulated without changing the speed of the driving member and without disturbing the .intermeshing of the gear train. It will be obvious that if I provide means by which the grate will be brought to rest at predetermlned intervals in each cycle, it will have the same effect as if the rate of speed of a constantly moving grate were changed.

one embodiment of mechanism by which the rate of travel of the grate may be controlled, I provide cycloidal gearingl as part of the train between the power s aft and the grate-driven shaft arranged in such a manner that by applying and releasing a brake, the grate may be moved or brought to rest. In the form illustrated, as best shown in Figr 2 as applied specifically to the arrangement shown in Figs. 1 and 2, the casing 15 is provided with an internal gear 29 and a cover 15a. Insidaof the casing 15 and keyed to the shaft 24 is a gear 30. Also on the shaft 24 and free to rotate thereon is a spider or frame 31 carrying pinions 32 and having a sleeve portion 33, the pinions 32 meshing in the internal gear 29 and the ear 30. The casing 15 and its cover 15a are greeto rotateon the sleeve 33 and the shaft 24, respectively. The gear 16 is keyed to the sleeve 33.

On the shaft 24 is keyed a brake drum 34 to which a brake may be applied in any desired manner, some forms of which will be described more fully hereinafter.

It will be noted that the casing l5 Aderives its motion from the belt 14 and the motor 11 in the form shown in Figs. 1 and 2 and that if the shaft 24 is free to turn, then rotation y of the casing 15 and the internal gear 29 will turn the gear 30 backward but will leave the spider 31, its sleeve 33 ,and the gear 16 stationary, so that no power will be transmitted to the shaft 10. By applying a brake or otherwisestopping the Abrake drum 34, the gear 30 is -held stationary and thus forms an abutment for the teeth of the pinions 32 as the latter are rotated by the internal gear 29.- This causes the spider 31 and its sleeve 33 to rotate to drive the pinion. 16 and the train of gearing to rotate the shaft 10.

In Figs. 5, 6 and 7, I have shown a means by which a brake may be applied to the drum 34 and released at predetermined intervals in the cycle of operation and also one in which the timing, both as to frequency and duration of the application of the brake, may be controlled b the operator to regulate the rate of travel o the chain grate. In the arrangement illustrated in Figs. 5, 6 and 7.,-a brake strap 3 5 is wound one or more tlmes around the drum 34, the lowerend of the brake strap being connected to a rod 36 held yieldingly by a spring 37. The .other end of the' strap 35 is connected to a brake lever 38 pivoted at 39 and having a cam roller 40, the end of the lever 38 being guided in-a slot in a member 41. It will be obvious that when the cam lever 38 is moved upward, the brake band 35 will be tightened on the drum 34 and hold the same to cause power to be transmitted from the driving shaft .to the shaft 10.

Inthe arrangement shown in Figs. 5, 6 and 7, I have shown a selective cam arrange- 'ment by which the brake band 35 may be tightened and released at selected predetermined intervals. In the frame is a cam shaft 42 having thereon a series of cams 43 which referably will be made vwith progressively increasing dwells or high arts from the right to the left of Fig. 6, t e cams at each end of the series preferably being each a complete circle, the one at the right `having the same radius as the low part of the other provide a handle 44 on the end of the shaft 42, the handle 44 being free to rotate on the shaft 42 but held against longitudinal movement relative thereto. Attached to the frame is a stop member 45 having a plurality of notches 46 arranged to be engaged by a segmental member 47 on the handle 44, the segment 47 being relatively long and the notches 46 .being relatively narrow, as best shown in Fig. 7.

With the parts in the position shown in Fig. 7, it will be obvious that the handle 44 and therefore the shaft 42 is locked against axial movement of the shaft. By rotating the handle 44 clockwise in Fig. 7, the member 47 passes 'out of engagement with one of the notches 46 and the handle 44 can then be moved sidewise, carrying with it the sha-ft 42 and the cams 43, to the desired position, when the handle is again dropped to the position shown in Fig. 7 and the shaft 42` thereupon locked in its selected position.

To insure that the cam roller 40 will not be in position to prevent the longitudinal motion of the shaft 42, I provide means by which when the handle 44 is raised to a position to move the shaft 42 axially, the roller 40 will be held to or preferably slightly above the largest radius of the cams 43. T o this end, I support the shaft 42 eccentrically in a rotatable frame supported at either end in the webs 12, 12i of the frame l2, the circular bearings of this rotatable frame being connected by a member 48 and having an eX- tension 48 with a groove 50 therein which is engaged by a pin 49 connected to the handle 44.

The rotation clockwise of the handle 44 turns the member 48 through the pin and slot connection 49, 50 and carries the shaft 42 to the right of Fig., 7 and downward,V and, at the same time, brings the member 48 into contact with the roller 40, the total effect being to permit the roller 40 to drop to its lowest position by reason of the fact that the cams 43 are carried to the right and away from the roller 40 but no lower than this lowest position by reason of its Contact with the member 48.

By this arrangement, the transmission of power from the power shaft to the shaft 10 is cut oi while the positions of the cams 43 are being adjusted. When the handle .44 is' brought back to its full line position of Fig; 7, cams 43 are returned to operative position and the member 48 moves outl of ,contact with the roller 40.

The' cam shaft 42, in the form illustrated,

vpart of the time, depending on the is driven from the power shaft by a gear 51' connected to the cas' 15 thro h a train 3f gears 52, 53, 54, 55 and 56, this train of gearing preferably being mounted in a pair of frames 57 pivotally suspended by luks 58 from a vfixed pivot 59 supported in the casing. By this arrangement, when the shaft 42 is moved to the right when the handle 44 is lturned clockwise in Fig. 7, the entire train of gears and their frames can also be moved slightly to the right in F' 5, so as not to disturb the meshing of t e teeth of such gear train, the ars 52 and 51 also remaining in mesh alt ough the extent of enga ment vof theirteeth may be somewhat shg tly chan ed. This train of gearing serves to reduce t e speed of the cam shaft 42 so that it makes only a relatively few turns to each complete cycle of travel of the chain grate.

It-,willbe noted that in the arrangement shown,-` the lmaximum rate of travel of the ratei-will be hadnwhen the handle 44 is to t e extreme right of Fig. 6, at which time, a large circular cam will be operatively positioned beneath the roller 40. The brake band 35 will thus be held tight at all times and power will be transmitted continuously from the power shaft to the 'shaft 10. At any position to the left of this position, the roller 40 will be in its raised position-on] lengt of the high part of the cam with which it isV cooperating, so that Ythe shaft 10 will be rotated only at intervals. Hence, the total rate of travel ofthe chain will be reduced. By moving the handle 44 to the position shown in Fig. 6, a cam 43, which is circular and of a diameter equal to the low part of the remainder of the cams, will be brought beneath the roller 40, so that the brakeband 35 'will be permanently released and the transmission of wer discontinued.

lldgtead of the mechanical arrangement for controlling-the rate of travel `of the grate, which I have just described, I ma use the electrical arran ement shown in ig. 8 for applying a bra e to thefdrum 34. In this I arrangement, brake pads 60 carried by brake levers 61 contact wit the drum 34, the lower ends of the brake levers'being'connected to a lever l62 which, in turn is connected to a lever 63 having a solenoid Vcore 64 cooperat# ing with the solenoid 65, so that when cur rent is supplied to the solenoid, the lever 63 will be raised to move the brake ads 60 away from the drum 34, these b epads normally being ressed against the drum 34' by the weight o the parts to which may be added any desired weight, for instance, a weight on the end of lever 63.

In order to apply the brake to the drum 34 selectively and at predetermined intervals, I provide a rotary switch 66 on a shaft 67 driven b a worm wheel 68 and. a worm 69 from a sliraft 70 which may reve power vwould be held against from the power shaft. The rotary switch 66 contacts successively with contact pieces 7l which are connected electrically to switch points 72, a switch bar, 73, slidable horizontally connecting as many of the switch points 72 as may be desired with a bar 74. A source of electrical energy is connected on one side to the bar 74 and on the other to the solenoid 65, the wire 7 5 extending from the solenoid to the rotary switch 66.

It will be obvious that in the arrangement just described, as the rotary switch 66 contacts with a switch point 71, the lead to which is electrically connected the bar 74, energy will be supplied to the solenoid torelease the brake pads 60 and that, by sliding the switch bar 73 tothe left of Fig. 8, as many of the switch points as desired may be connected so as to become active when contacted by the rotary switch 66 in each turn of that switch. By this means, the number of times in each cycle in which the brake is applied and released may be selected and after being selected, will operate at predetermined intervals.

Because in the arrangement shown, the drive power is at intervals removed from the shaft l0, it would be possible if the chain grate had any slack therein, for the weight of the fuel on the chain to cause the grate to move backward to take up this slack. In

order to prevent this, I provide a friction brake on the gear train connecting the power shaft with t e shaftlO, so that the shaft 10 may be rotated freely forwardly but ackward motion. One form of such an arrangement is shown in Fig. 9, in which a brake drum 76 con'- nected to the gear 16 and therefore to the shaft 10 is provided with a brake band 77 and a brake pad 78, the ends of the band 77 being connectedvby links 79 to a lever 80 having a in 81 engaging the brake pad support. n the pin 81 isa lever 82 having a pin 83 enga ing with a fixed .member 84.-h

A spring 85. olds the friction band 77 against counterclockwise motion in Fig. 9,

the shaft 24 rotating counterclockwise when the shaft 10 is being driven. n

In this arrangement, if the drum 76 is rotated clockwise, as would be the case if the slack in the chain turned the shaft 10 backward, the friction would then carry the band 77 clockwise and this would cause the band 77 and thepad 78 to be pressed against the drum 76 by reason of the holdin of the pin 83 against rotation by the memer 84 and the unequal arms of the member 80. This would vlock the drum 76 'nst clockwise motion and therefore hol the shaft 10 against backward motion. It will be understood that the arrangement which I have shown is merely illustrative and that the embodiments of my invention may be widely varied. It will also lao be understood that some of the features of my' invention' may be' used independently of other features.

I claim:

l. In combination, a chain-grate stoker drive comprising a driven shaft, a continuously moving power shaft, gearing between said shafts, means, driven from said power shaft, to interrupt the transmission of power l 4 means, driven vfrom said power shaft, to interrupt the transmission of power from said power shaft to said driven shaft at predetermined'intervals while said power shaft rotates at Aa constant speed, said means comprising a cam roller, a cam shaft, a plurality of differently shaped concentric cams on said shaft, a handle on said cam shaft and connected thereto to hold the handle against motion axially of said cam shaft and to permit said shaft to rotate in said handle, a c am roll lifter attached to said handle, a fixed stop to prevent lateral motion of said handle and a member on said handle toengage said stop, said stop, member and lifter being constructed and arranged to bring lsaid lifter into operative position to'lift said roller when said handle is turned to move said member out of engagement with said stop. Y

3. A driving mechanism'for a chain-grate Stoker comprising a grate-chain-driven shaft, a continuously moving power shaft,

a train of gearing between said shafts,

means, driven from said power shaft, to interrupt the transmission'of power from said power shaft to said driven shaft at predetermined intervals while said power shaft rotates at a constant speed, said means comprising a cam roller and a plurality of differently shaped concentric cams, means to bring said cam roller into operative relation with a selected cam, and means to separate the peripheries of all of said cams from said cam roller while the cam roller and cams are being brought into such selected relation.

4. A driving mechanism fora chain-grate stoker comprising a grate-chain-driven shaft, a continuously moving power shaft, a train of gearing between said shafts, means,driven from said power shaft, to interrupt the transmission of power from said power shaft to said, driven shaft at predetermined intervals while said power shaft rotates at a constant speed, said means comprising a cam roller and a plurality of differently shaped concentric cams, means to move said ca ms laterally to bring a selected cam into operative relation tov said cam roller,l and means to separate the peripheries of all of said cams from said cam roller while said cams are being moved laterally.

5. A driving mechanism for a chain-grate Stoker comprising a grate-chain-driven shaft, a continuously moving` power shaft, a train of gearing between said shafts, means driven from said powershaft, to interrupt the transmission of power from said power shaft to said driven shaft at prede termined intervals While said power shaft rotates at a constant speed, said means comprising a cam roller, a cam shaft, a plurality of differently shaped concentric cams on saidshaft, a handle to move said cams and said cam roller relatively longitudinally of the cam shaft, to bring the cam roller into operative relation with a selected cam, and a cam roller lifter connected to said handle ler, and means to separate the peripheries of all of the cams while the cam roller and the cams are being so moved relatively.

FREDERICK WILLIAM HoLLIcK.'

CERTIFICATE 0E CORRECTION.

Patent No. 1,724,711. Granted August 13, 1929, 10

FREDERICK WILLIAM IIoLLICK.

It is hereby certified that error appears in Ythe printed specification'of the above numbered patent requiring correction as follows: Page l, line l0, for "Fig. 4a front" read "Fig. 4 afront", page 4, claim 5, strike out line 91, and insert instead "to separate said camroller and the peripheries"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of September, A. D. 41929.

M. I. Moore, (Seal) Acting Commissioner of Patents. 

